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Philco Model 41-296X with 41-285 modified chassis
#20

Hmmm...okay.

Do you have the schematic for this radio?

Locate part (58). This is the audio output transformer. See where the black wire and the white wire goes? Each of those wires go to the plate of a 41 tube. The schematic also gives the resistance measurements: 170 ohms and 190 ohms. 170 between one half of the winding and the center tap lead (black with white tracer), 190 between the other half and the center tap.

So if you measure between the two plates of the 41 tubes - in other words, between the black lead and the white lead - you should get in the neighborhood of 360 ohms.

Note there is no measurement given on the schematic of the right side of the winding - this is the secondary. You should measure only a few ohms on this winding.

Yes, those three wires do have little "bumps" or "berries" on them. All audio output transformer primary leads get that way in these 1939-42 Philcos. I don't know why.

Some time spent in learning the symbols of a schematic diagram will be a big help here. This link does not include symbols for tubes, but will get you started:
http://www.wisc-online.com/objects/index...ID=DCE1902

And here's another page, with tube symbols:
http://library.thinkquest.org/10784/circ...mbols.html
It's like learning to read a road map. A schematic diagram is sort of a road map of your radio; it shows how everything is connected.

Edit: Oh, yes, please DO replace that fried 160 volt cap with a new 450 volt cap!

--
Ron Ramirez
Ferdinand IN


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Re: Philco Model 41-296X with 41-285 modified chassis - by Ron Ramirez - 12-02-2009, 08:26 AM



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